La Berceuse
by AndSheWasBeautiful
Summary: "Sun's getting real low," she says, her eyes darting towards the huge window above his desk, towards the sun as it dips in the sky, behind the horizon, making the fire red of her hair blaze, her smooth legs glowing from where they peek out from the bottom of her dressing gown. The origins of the infamous lullaby. BN


"Hey big guy."

She is stealthy as always, never drawing an ounce of attention to her presence, and for this reason he starts, a little jump enough to knock the graph he's been staring intently at for the past half hour slightly out of place in the hologram before his eyes. Bruce Banner blinks, taking his glasses off to rub at his eyes, puffy with exhaustion. He tries to remember how long he's been at work, taking a moment to gaze at the papers strewn across the desk and curses himself for his innate inability to keep track of the time. He remembers suddenly, why he was disturbed in the first place, turning his head gently towards her voice, to see her lithe form leant against the door frame to the lab.

Her head is tilted to once side, her hands in her pockets, her hair falling softly around her cheekbones, newly chopped with her own pair of scissors, slightly damp at the ends. She has no doubt just left the shower, as she uses the towel draped around her neck, he notices, to dab at the edges of her face. She is bathed in an orange-gold glow, making the fire red of her hair blaze, her smooth legs glowing from where they peek out from the bottom of her dressing gown. Her arms are folded across her body, hugging herself round the sides, a soft smirk playing around the corners of her lips.

She is a _goddess_.

"Sun's getting real low," she says, her eyes darting towards the huge window above his desk, towards the sun as it dips in the sky, behind the horizon. Bruce glances towards the window, grateful for an excuse to look away from Natasha, the intensity in her mossy green eyes making his stomach churn with butterflies. He frowns at the window and the sun, twisting his hands together just for something to _do_ with them. He opens his mouth to speak when he realises she has moved closer to him, further into the room, the towel slipping down from around her neck in her hand to rest at her side as she watches him.

He tries to lick his lips, but his mouth is suddenly dry.

She smiles again, that little half smirk, and he gulps back the sandy dryness, cursing her and then cursing himself for cursing her.

"Uh... yeah," he answers, _brilliantly_ , the brilliant Bruce Banner being brilliantly _boring_. Natasha's eyes light up at that, and she throws her head back in a little snort of laughter, brows raised at him.

"You look exhausted Bruce," she says, eyes mirthful, taking a careful step closer to him, hugging herself once again, drawing her dressing gown in tighter to her curves as her toes curl up. He grins sheepishly, nodding his head with exaggerated enthusiasm, a nervous laugh in the back of his throat.

"I... _feel_ exhausted, Natasha," he says, breathing out a long, low breath, expelling some of the anxiety she summons up within him, a genuine smile stretching across his face as he interlocks his fingers, together and apart, together and apart, calming himself as he so often finds himself doing.

She settles on the edge of another work bench, brow raised, grin not subsiding. She tilts her head towards him, doing her best to look like a scolding school teacher, and he feels a flutter in his chest which he hides instantly with an unsure cough, and a glance away from her.

 _I adore you._

She taps out a beat on the table, bobbing her head in time with her tapping, her one foot which is suspended in midair from where she rests on the workbench swinging in tandem with her self-made beat.

"Hey-big-guy... the-sun's-get-ting-low."

She doesn't sing the words, but she speaks along with her rhythm, her voice taking on a funny little musical twang, rough and altogether utterly tuneless.

Bruce can't help the smile that sneaks its way onto his face, and the snort of a laugh which follows soon after. Natasha starts to laugh to, soft and husky and she rolls her eyes at him.

"It was an _idea_ for a lullaby, Banner. They didn't train me to be a singer you know," she shoots at him, a little note of disdain in her voice and he raises his hands in defence as though surrendering to her, shaking his head, trying to manage his increasingly wide smile.

"Forgive me, Ms Romanoff - you know I would never intentionally insult your singing voice," he says, his shoulders slumped in comfortable relaxation, once again a slave to the wave of calm Natasha brings to his mind (prior, of course, to making his palms sweat and his knees tremble in a nervous tremor).

"Or my lullabies," she adds, pointing her finger accusingly at him. He grins and nods his head, settling his hands upon his knees again.

"Or your lullabies," he agrees, eyes warm and full of Natasha, heart not far off just that.

* * *

He is loose, and he is wild and he is frantic and Natasha knows it will kill him, _kill him_ , if Banner comes round from this stupor and finds he's harmed a civilian.

This wasn't _supposed_ to be a Code Green and he wasn't _ready_ and if those stupid _, ignorant_ bastards of civilians hadn't started screaming and shouting and throwing things at him when they saw him poke his head out of the quinjet to throw Clint another quiver of explosive arrows, the Other Guy never would have taken matters into his own hands.

And now the idiots were running around, practically begging to be trampled by the Hulk and Natasha wonders if these people who are so traumatically frightened of him, remember all the times he has helped to save their pathetic little lives.

Natasha knows of the monsters in this world, and Bruce Banner is not one of them.

Steve is screaming something in her earpiece about Banner being too close, Thor is too far, Tony is preoccupied and _don't go for him on your own Natasha, you will only hurt him more if something happens he can't control._

Poor Steve, she thinks - he still doesn't understand how much I struggle with orders. She pulls the communicator out of her ear and tucks it into her back pocket, preferring to attempt to calm the Hulk without Captain America barking _cease and desist_ at her.

She skids to a halt at the end of a road junction, the last of a group of panicking civilians, shoving past her like a herd of wildebeest and she rolls her eyes, pushing out past the throng and into the centre of the road junction, where the Hulk stands, growling and panting, next to an overturned car. The sun is setting, dying the sky a bloody red as a sliver of sunlight remains resting along the horizon, giving way to the night sky and the sprawling stars.

She is alone, and her heart is pounding against her chest as she meets his eyes, dark and so like Bruce's that she finds her throat catching.

The Hulk roars at her, soul shattering and bone crushing with ferocity.

She speaks before she knows what she is doing, and she does not hide her fear, rather accepts it and moves on, just as she was always taught to do.

"Hey big guy."

The Hulk snorts and shuffles in agitation, lunging forwards towards her, unpredictable and deadly, and she hunches down, keeping her eyes trained on his, her hand reaching out for him, the tremble of her entire body suppressed down as far as it will go, so she does not betray her heart stopping fear.

The Hulk watches her hand, the twinge of Banner's humanity shining in those deep eyes, and Natasha watches as the creature struggles, and she wonders for what must be the millionth time since they have met, what the war within Bruce's head _sounds_ like.

Her hand remains steady, and she splays her fingers out with purpose.

"The sun's getting real low."

The air seems still around them, and the seconds seem like they last forever as the hulking beast before her watches her hand and snorts gruffly, before reaching out and brushing his own massive digits against her smaller ones.

The green of his skin is clammy and rough, and Natasha holds her breath in sheer bewilderment - no one else has ever been so close to the Other Guy, as to actively feel the texture of his skin. He turns his palm over, and Natasha reaches out, sliding her hand softly up his wrist, all the while her eyes never leaving his own. She pats his skin and removes her hand, standing up straight, slowly, never taking her gaze away from his face.

He grunts and turns, lumbering away from her, all the while shrinking down, becoming less of a beast and more of a Banner with every step that he takes, before he falls in a heap, his clothes torn and his body battered and before she knows what she is doing, Natasha is tripping over her own feet to throw herself at his side and make sure he is alright. His head is pressed sharply to the concrete of the road, and she shoves him over with all her might, as his head rolls backwards and his eyes open to all but slits, deep and brown and she has to clench her hands into tight little balls on the cold ground, to stop herself from fisting them in his hair and pulling him close.

He shakes his head, and she sees the overwhelming fear the Other Guy instils within him, as he has been shaken to his very core and he croaks out his next words.

"You're _insane_."

She shakes her head, fighting to keep her face as expressionless as she can, her quirk of a grin finding its way onto her face as she inclines her head towards him.

"And you're exhausted," she murmurs back, to which the rightfully assumed exhausted Bruce Banner shakes his head in disbelief and hovers on the edge of unconsciousness below her. She raises a brow and leans down, checking his heart rate as she does so, her lips close to his ears. "I would have sung, but as I recall, you insulted my singing voice..."

He wheezes a rasping laugh, his eyes rolling back in his head as the toll that the transformation takes on his body finally catches up with him, and he licks his cracked, dry lips as he croaks out his words.

"But never your lullabies."

Natasha laughs at that, shaking her head at the dork that lies on the ground beside her knees, and allows herself to brush a greying curl back from his forehead.

"No, never my lullabies."

* * *

 _i will buy a diamond ring for you, i will sing for you, i'll do anything for you to see you smile._


End file.
